28 U.S. Code § 463 - Expenses of litigation

Whenever a Chief Justice, justice, judge, officer, or employee of any United States court is sued in his official capacity, or is otherwise required to defend acts taken or omissions made in his official capacity, and the services of an attorney for the Government are not reasonably available pursuant to chapter
31 of this title, the Director of the Administrative Office of the United States Courts may pay the costs of his defense. The Director shall prescribe regulations for such payments subject to the approval of the Judicial Conference of the United States.